Currently, there are many methods to clean the air of a room or an environment. Conventional methods include known filtering units which reside inside the room environment and filters the air. These known filtering units may be permanent or portable and will filter the air of a room or area, filter the air continually as they operate, drawing the air into the unit, filtering the air and then returning it to this same environment.
Some of these systems may be less effective due to having to use filters, which may not be of the needed or desired level of filtration due to the amount of airflow restriction caused by the filters. Many known filtering systems are not equipped with a sufficient filter, such as a HEPA (High Efficiency Particulate Air) grade filter. HEPA filters can be rated to remove 99.97% of all particles more than 0.03 microns. The problem facing the use of these HEPA filters, such as a H17 class filter, is that they can restrict the airflow, which passes through the filter. This restriction creates a backup and limits the amount of air a known air filtration system may be able to filter. In addition, the amount of air that passes through a HEPA FILTER, such as a class H17 filter, means that the amount of air that can be filtered in a certain time period, such as a minute or hour, is severely reduced. These systems will require powerful blowers or motors to move the air through HEPA filtered, rated H17, and therefore would use more electricity and may not be as efficient as would be desired.
Some other problems with known air filtration systems are their inability to utilize carbon or other ingredients within the filters, due to the drop in pressure such ingredients may create and the inadequacy of the motors driving the blowers to push air sufficiently through the filters. Therefore many of these known air filtration systems compromise the quality of the filtered air for the desired air pressure.
There are several problems faced by the known air filtration systems placed inside rooms. Often the small units use small motors or fans, which are not adequate to create enough Air Exchanges per Hour (AEH) to keep the room clean. Sometimes they utilize small motors in order to be quiet and when combined with a HEPA or high MERV rated filter, do not create enough air flow to exchange the air in the room an adequate number of times in a minute or hour to be effective or to create the desired effect and impact. Lack of air movement through the filters also reduces the air velocity in these systems. The reduced air velocity limits the distance the air will travel in a directed flow and will reduce the ability of the unit to move air in at a greater distance from the unit. This will prevent smaller units to accommodate larger square foot and cubic foot rooms.
Smaller known air filtration systems lack enough air velocity such that when added to a system, which may include a HEPA filter of 99.97%, the smaller system will drastically decrease the overall air velocity due to its inability to properly exchange the air in the room, or what is referred to as “air exchanges”.
Other problems with known air filtration systems relate to the ‘CFM’ rating of the motor driving a blower. The CFM rating of a motor or fan is the ‘Cubic Feet per Minute’ that the motor can exchange. For example in a room that is 10 ft×10 ft×8 feet tall, or 800 cubic feet, an air filtration system rated at 200 CFM's would change the air in a room, one time every four minute or 15 times per hours or 15 AEH. This simple calculation does not necessarily mean that all the air in the room actually does exchange in that time. Using a smaller CFM motor in conjunction with a HEPA filter will create a resistance and back pressure to the air velocity and therefore may result in the air not being moved at the rated 200 CFM's, but may be decreased to ‘an effective’ CFM of less than 200 CFM, perhaps 100 CFM, which means that the known air filtration system would only ‘exchange’ the air, 1 (one) time every 8 (eight) minutes, or 7½ times per hour, as would be expected.
Other problems encountered with known air filtration systems is their inability to exchange the air in a room, at high rates or which is sufficient to maintain a sufficiently clean area for the purpose at hand. There are currently room air purification devices which claim to do, as an example, a 700 sq. ft. room, 77 cu. ft. assuming 8 foot ceiling, but the only exchange the air in the room 4 times an hour, with a filter rated at 10 MERV. At the rate of 4 AEH and a MERV 10 filter, the unit would not be able to keep the room clean, if a few people occupied it Other problems encountered by known air filtration systems is the inability to move the air on the far sides of the room, due the restrictions expressed above, and the lack of velocity of the moving air. The combination of a smaller motor and HEPA filter will reduce the ability for the air to maintain a velocity which will allow it to reach the far corners of the volume or room to be cleaned, and also reduces the creation of turbulence amongst the particulates and contaminants in these further portions of the room or volume.
At present many known air filtration systems on the market today, especially room known air filtration systems, use a single fan/blower or motor to move the air, one set of filters, a single airflow or airstream, and a plenum. If these known air filtration systems use a 99.97% HEPA filter for the removal of particulates from the air, they will be restricted in their performance and will not accomplish expected results, due to the backpressure and limited airflow. For these known air filtration systems to be able to move enough air, manufacturers may use a lesser grade filter such as an 90% filter, or a Merv 8 rating which would only remove much larger particulates, such as 5.0 micron and larger.
Currently, there are individual and industry misconceptions of the methods for cleaning and moving the air within rooms. These misconceptions relate to the relationship between the air exchanges and the grades of the filters. Many believe that in order to be effective a high grade HEPA filter, which may be a 99.97% HEPA filter, which captures up to 0.3-micron particulates.
A third problem facing current known air filtration systems is that to move air through a 99.97% HEPA filter, a powerful motor is required and in most cases the more powerful motors make more noise that is suitable for many environments and require more energy, which will make it more costly to operate. The noise issue is difficult to solve due to minimum CFM requirements to move air through a HEPA filter.
Another problem facing current air filtration systems is that they rely on one set of filters and blowers to clean the desired air environment. This makes these products to rely on the ability of that one filter system to be able to accomplish these goals, and cannot take advantage of utilizing different filter ratings for different purposes. The mixing of filters and blowers will allow a greater diversity of use of the invention.
Another problem facing existing air filtration systems is that they only contain one blower and filter system. If these system contain blower is capable of exchanging the air 10 times per hour, then this is there limit. One blower and filter system they can only change the air in relationship to the CFM's of that single system.
It would be highly desirable to provide an air filtration and purification apparatus that overcomes the above listed and other disadvantages.